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GOLDSBURY POND, OF RUTLAND, VERMONT.

BliEACHlNG wooo AND OTHER MATERIAL.

part of Letters Patent No. 351,069, dated October 19, 1886.

195,448. (No specimens.)

SPECIFICATION forming Application filed December 12, 1885. Serial No.

this chemical change quite a percentage of oxygen is ireed or developed,and in its nascent state is very active, and with the free sulphurous acid cleanses and partially bleaches the pulp and frees it from the obstacles that have always barred the way of making these kinds of pulp perfectly white. In an hours time this treatment is complete, and more water is let in and the charge rinsed thoroughly when it is ready for the chlorine bath, where it will soon be made perfectly white with but a trifling expense.

There is no particular apparatus required for this treatment. The machines now used for Washing and bleaching pulp in the paper mills and manufactories are all that is required to carry this process into effect, with the addition of the apparatus to make the sulphide of lime.

I claim- The process of removing stains, tints, or dis colorations from wood pulp or other material in process of bleaching. the same consisting in a bath of sulphide of lime. decomposing the latter with sulphuric acid, thereby freeing the sulphurous acid and developing oxygenwhich,

To all whom it may Be it known that I, GOLDSBURY H. POND, a citizen of the United States, residing at Butland, in the county of Rutland, State of Ver-' mont, have invented certain new and useful Improvements in Bleaching Wood and other Material, of which the following is a specification.

The nature of my invention consists in improvements in the manufacture of pulp from wood.

It has thus far, in the manufacture of wood pulp, been considered in practical work to be impossible to change the color of ground wood from its natural tint, and the wood pulp made with the alkaline process can only be bleached to a very light cream color.

The object of my invention is to produce white pulp from any ground wood; also, to produce white pulp from the products of any of the alkaline processes by an inexpensive mode.

To carry my invention into effect I first prepare a sulphide of lime with the apparatus illustrated and the method described in my application for Letters Patent, Serial No. 185,447.

After the pulp is made in the usual way an in conjunction with the free sulphurous acid, washed, beforeit is discharged from the washer, cleanses and partially bleaches the pulp, sub- I introduce a small amount of the sulphide of stantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

GOLDSBURY H. POND.-

lime with water enough to move it with the part of the machine made for that purpose. After the sulphide of lime is thoroughly mixed through the mass of pulp, I then add a small quantity of sulphuric acid, which decomposes the sulphide of lime,combining with the same and liberating the sulphurous acid. During Witnesses:

N. A. ACKER, WILLIAM PAXTON. 

